JP7319737B2 - stacked reactor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a layered reactor, and more particularly to a layered reactor for reactions involving solid deposition, in which a solid catalyst is laid on the inner wall surface of the reactor.

In a chemical reaction using a solid catalyst packed in a flow reactor, if the reaction involves solid deposition, there is a problem that the deposit accumulates over time and the pressure loss in the reactor increases. For example, in a reaction involving carbon deposition, such as methane reforming, deposited carbon accumulates in the catalyst pores or between the catalyst particles to fill the space. blockage, increase pressure loss, and eventually stop operation. In that case, in order to remove the deposited carbon, maintenance such as combustion of carbon with an oxidizing agent on the catalyst and replacement of the catalyst is required. It is practically advantageous.

A plate reactor has been proposed as a reactor to solve these problems. The plate-type reactor has a sandwich structure in which a gasket having a slit for forming a flow path is sandwiched between two plates, and at least one or both of the two plates communicate with the slit. A plate-type reactor having one fluid inlet and at least one fluid outlet, wherein a solid catalyst is embedded and fixed in grooves provided on the wall surfaces of the two plates of the plate-type reactor facing the flow channel to reform methane. It is reported that by performing the above, it was possible to suppress the increase in pressure loss due to channel blockage compared to the case of using a conventional packed reactor in which a solid catalyst was packed in a tube (Patent Document 1, Non Patent Documents 1 and 2).

JP 2017-144403 A

Fukuda et al., "Study of methane reforming using a plate reactor", Abstracts of the 81st Annual Meeting of the Society of Chemical Engineers, D303 (February 2016) Fukuda et al., "Study of methane reforming using a plate-type reactor (2) - Reforming of concentrated dry gas -", Abstracts of the 48th Autumn Meeting of the Society of Chemical Engineers, LQ130 (August 2016)

In the plate-type reactors in each of the prior art documents mentioned above, a powdery catalyst sieved to a particle size of 0.3 mm or less is used as the catalyst buried and fixed in the groove.
However, from the viewpoint of suppressing channel clogging, it is advantageous to increase the ratio of void space inside the reaction vessel (void ratio), and increase the particle size of the solid catalyst to lower the bulk density of the catalyst layer. By increasing the void fraction in this manner, further suppression of channel clogging can be expected.

However, when a solid catalyst having a large particle size is used, there is a problem that it becomes difficult to firmly fix the solid catalyst to the wall surface of the reactor.
That is, when a powdery catalyst having a small particle size is used, the method of embedding and fixing it in the groove provided in the plate includes a method of fixing by compression molding, and a method of fixing with a fixing liquid (binder) such as an aluminum nitrate solution ( Patent Document 1 [0010]) can be used, but when a granular catalyst having a large particle size is used, the contact area between the catalyst particles or between the catalyst and the wall surface of the reactor becomes insufficient. The method of (1) has the problem that the solid catalyst easily peels off from the wall surface of the reactor, making it difficult to firmly fix it.

The present invention has been made in view of the above circumstances, and a layered reaction for reactions involving solid deposition, in which a plurality of plates, including the above-described plate-type reactor, are stacked via gaskets An object of the present invention is to provide a layered reactor capable of preventing falling-off and scattering of a solid catalyst even when the particle size of the solid catalyst is increased.

As a result of various investigations in order to solve the above problems, the present inventors have found that a solid catalyst in the form of powder or granules having a particle size of greater than 0.3 mm is used in a layered reactor for reactions involving solid deposition. Then, by covering the surface of the solid catalyst laying portion provided on the inner wall surface of the reactor with a support such as a mesh having openings smaller than the particle size of the fixed catalyst, the solid catalyst particles will fall off even if they move slightly. The inventors have also found that it is possible to prevent the particles from scattering (hereinafter, "fixing"), and have completed the present invention.

That is, the present invention for solving the above problems is as follows:
[1] A layered reactor for reactions involving solid deposition,
a channel formed by stacking a plurality of plates at predetermined intervals via gaskets;
a fluid inlet and a fluid outlet provided in one of the plates and communicating with the channel;
a powdery or granular solid catalyst with a particle size of greater than 0.3 mm;
a laying portion for the solid catalyst provided on a wall surface facing the flow path;
a support covering the laying portion of the solid catalyst and having openings smaller than the particle size of the solid catalyst;
with
A stacked reactor in which the solid catalyst is fixed to the wall surface by the support.
[2] The stacked reactor according to [1], wherein the portion where the solid catalyst is laid is provided in a recess provided in the wall surface of the plate or gasket facing the channel.
[3] The stacked reactor according to [1], wherein the solid catalyst-laying portion is provided on the wall surface of the plate or gasket that faces the channel and has no recesses.
[4] The stacked reactor according to any one of [1] to [3], wherein the support is sandwiched between one of the plates and a gasket.
[5] The layered reaction according to any one of [1] to [3], wherein the support has a restoring force and is compressed and fixed between the plates by surface pressure. vessel.
[6] The plate is
two plates arranged on the bottom and top layers of the laminated structure;
a straightening plate having a plurality of through-holes disposed between the two plates,
The stacked reactor according to any one of [1] to [5], wherein the fluid inlet and the fluid outlet are arranged opposite to each other with respect to the straightening plate.

According to the present invention, it is possible to provide a layered reactor in which a solid catalyst of any particle size and shape can be fixed so as not to fall off or scatter. Since the catalyst can be fixed, it becomes possible to increase the void fraction in the reaction vessel. In addition, in hydrogen production or synthesis gas production by methane reforming, by using the stacked reactor of the present invention, it takes a longer time than before to block the flow path due to carbon deposition or to maintain the catalyst. Therefore, maintenance frequency can be reduced, and as a result, operation can be performed with reduced running costs.

Appearance of a stacked reactor according to one embodiment of the present invention FIG. 2 is a perspective view showing a mode in which a solid catalyst is laid on a wall surface facing a channel in one embodiment of the present invention; 1 is a diagram schematically showing an example of a method for fixing a solid catalyst in an embodiment of the present invention, and is a perspective view of the lower plate 2 as seen from above; FIG. 1 is a diagram schematically showing an example of a method for fixing a solid catalyst in an embodiment of the present invention, and is a cross-sectional view of upper and lower plates 2, 2 and a gasket 3 viewed from the side; FIG. FIG. 4 is a diagram schematically showing an example of a method of fixing a support in one embodiment of the present invention, and is a cross-sectional view of upper and lower plates 2, 2 and a gasket 3 viewed from the side; FIG. 4 is a perspective view showing a mode using plates of various shapes as another embodiment of the present invention; FIG. 3 is a perspective view showing a mode in which a fluid inlet and a fluid outlet are laid on the same plate as another embodiment of the present invention; FIG. 4 is a perspective view showing an aspect using three or more plates as another embodiment of the present invention; Diagram explaining the definition of void fraction Diagram explaining the definition of catalyst layer dimensions (L, W, H) in a catalyst wall reactor Diagram explaining the definition of catalyst layer dimensions (L, d _i ) in a tubular catalyst-packed reactor FIG. 2 is a diagram showing temporal changes in pressure loss and methane conversion rate in Examples and Comparative Examples of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on embodiments, but the present invention is not limited to the embodiments.

A stacked reactor 1 according to one embodiment of the present invention (hereinafter referred to as "this embodiment") is arranged between a plurality of plates 2 and 2, as shown in the external view of FIG. A flow path 4 is formed by the opening of the gasket 3 and the inner surface of the plate positioned at the opening. 5 and a fluid outlet 6 are provided.

In the stacked reactor according to the present embodiment, the plates 2, 2 and the gasket 3 are superimposed (stacked) and positioned, and each element is compressed and deformed by applying a surface pressure in the stacking direction to compress and deform the gasket. After filling the gaps between them, the plates are assembled by fixing them together. The method of applying surface pressure and the method of fixing the plate are not particularly limited. .

The solid catalyst is preferably laid along the inner wall of the channel 4 in order to reduce the pressure loss of the fluid.
FIG. 2 is an exploded perspective view showing a manner in which the solid catalyst 7 is laid on the wall surface facing the channel 4 in this embodiment. or, as shown in (b), in a recess provided in the wall surface (defining the flow path) facing the flow path of the gasket. , and combinations of these aspects.
Moreover, in each of the above-described aspects, as shown in (c), plural types of solid catalysts 71 and 72 may be laid at plural locations along the flow path.
Furthermore, in the examples shown in FIGS. 2(a) to 2(c), the solid catalyst is laid in the recess provided in the wall surface facing the flow path 4, but it is laid on the wall surface without the recess. Also good.

In the present invention, a powdery or granular solid catalyst having a particle size of more than 0.3 mm is covered with a support having openings smaller than the particle size of the solid catalyst, which covers the laying portion of the solid catalyst. characterized in that it is fixed to

3 and 4 are diagrams schematically showing an example of a method for fixing the solid catalyst 7 in the present embodiment. FIG. 3 is a perspective view of the lower plate 2 as seen from above, and FIG. It is a cross-sectional view of the plates 2, 2 and the gasket 3 as seen from the side, and the arrows in the drawing indicate the flow of fluid.
In this embodiment, as shown in FIGS. 3 and 4, the solid catalyst 7 is laid in recesses provided in the walls of the plates 2, 2 facing the flow path 4. By covering with a support 8 such as a mesh having openings smaller than the particle size of the solid catalyst 7, the solid catalyst 7 is fixed in the layered reactor without falling off or scattering.

3 and 4. For example, the solid catalyst 7 may be laid on the surfaces of the plates 2, 2 without recesses, or only one of the plates 2, 2 may be provided. in which case the solid catalyst 7 is likewise fixed using a support 8 .

The shape of the support 8 is not particularly limited as long as it has meshes smaller than the particle size of the laid solid catalyst 7. Examples thereof include mesh, cotton-like material, non-woven fabric, and sponge-like porous material. , a porous body provided with punching holes, and other porous bodies are used.

In addition, the material of the support 8 is not particularly limited as long as it does not react with the raw materials and reaction products under the conditions of use of the stacked reactor. , SUS440C, etc.), aluminum materials (A2017, A5052, A5056, A6061, A7075, etc.), brass materials (C3601, C3604B, etc.), iron materials (S10C to S45C, SCM415, SCM420, SCM435, SCM440, SUJ2, SKD11) , SKS3, SUM22D, SUM24L, STKM13A, SCR420, etc.), titanium, nickel-based materials (Inconel (registered trademark), Hastelloy (registered trademark), Monel (registered trademark), Incoloy (registered trademark), etc.), and copper. Metal materials, organic compound materials such as acrylic resins, and ceramic materials such as alumina and quartz can be used. In addition, the material is not limited to a single material, and may be coated with plating, vapor deposition, or the like.

Next, a method for fixing the support 8 in the stacked reactor 1 will be described.
In the examples shown in FIGS. 3 and 4, after the support 8 is fixed to the walls of the plates 2 and 2 with an adhesive or the like, the plates 2 and the gasket 3 are laminated to assemble the laminated reactor. However, the method of fixing the support 8 is not limited to this, and the support 8 may be fixed at the same time as the stacked reactor is assembled.
For example, when assembling a stacked reactor, a method of sandwiching the support 8 between one of the plates 2 and 2 and the gasket 3, or a method of using a support 8 having a restoring force and applying between the plates 2 and 2 A method of compressing and fixing by surface pressure and the like can be mentioned.

The cross-sectional view of the upper and lower plates 2, 2 and the gasket 3 in FIG. , 2 are compressed and fixed by the surface pressure applied between them.
In the figure, an example is shown in which a flocculent material such as quartz wool or a sponge-like porous material is used as the support 8 having a restoring force. It is also possible to use a porous body such as a mesh of

According to the method of fixing the solid catalyst in the stacked reactor of the present invention, the particle size and shape of the solid catalyst 7 are not particularly limited, and the size of the particle size can be adjusted by selecting the opening of the support 8 to be used. It can be fixed so as not to fall off or scatter even if it has any shape.

As will be described later, the particle size of the solid catalyst 7 is particularly important as one of the conditions for guaranteeing the reaction performance.・It can be said that the action and effect of being able to be fixed so as not to scatter improves the reaction performance in the stacked reactor and is very useful in terms of design.

In the conventional solid catalyst fixing method described in Prior Document 1, etc., in a layered reactor, when the particle size of the solid catalyst is increased, a large amount of binder is used to prevent it from falling off or scattering from the inner wall surface of the flow channel. is required, the void fraction is reduced, making it difficult to suppress pressure loss. In addition, since the solid catalyst is buried in a large amount of binder and the number of reaction points is reduced, the reaction rate is reduced.
On the other hand, according to the fixing method of the present invention, the solid catalyst can be fixed without using a binder so as not to fall off or scatter. In the quality reaction, by making the particle size of the solid catalyst larger than 0.3 mm, the void fraction can be increased and the pressure loss can be suppressed. A methane conversion rate comparable to or higher than that obtained using a tubular catalyst packed bed reactor can be obtained.

Other elements and members constituting the layered reactor of the present invention will be described below.

(plate)
The material of the plate 2 is not particularly limited as long as it does not react with the raw materials and reaction products under the conditions of use of the stacked reactor 1 and does not deform. SUS420J2, SUS304, SUS440C, etc.), aluminum materials (A2017, A5052, A5056, A6061, A7075, etc.), brass materials (C3601, C3604B, etc.), iron materials (S10C to S45C, SCM415, SCM420, SCM435, SCM440, SUJ2, SKD11, SKS3, SUM22D, SUM24L, STKM13A, SCR420, etc.), nickel-based materials (Inconel (registered trademark), Hastelloy (registered trademark), Monel (registered trademark), Incoloy (registered trademark), etc.), titanium and copper metal materials such as those mentioned above, organic compound materials such as acrylic resins, and ceramic materials such as alumina and quartz. In addition, the material is not limited to a single material, and may be coated with plating, vapor deposition, or the like.
The shape of the plate 2 is not particularly limited as long as it is a plate shape, and as shown in FIG. good.
The size of the plate 2 is also not particularly limited, and may be determined as appropriate in consideration of the availability, the required amount of the reaction product, the ease of control of the reaction, and the like. An example is a length of 10-1000 mm, a width of 1-1000 mm, and a thickness of 0.1-10 mm.

(gasket)
The gasket 3, in addition to the function of defining the flow path 4 together with the plate 2, has sealing properties to the extent that the internal fluid does not flow out to the outside through the sealing surface of the gasket 3. As shown in FIG.
Materials for the above-mentioned sealing gasket include engineering plastics such as PTFE, super engineering plastics, natural rubber, synthetic rubber (nitrile rubber, chloroprene rubber, ethylene propylene rubber, fluororubber, silicone rubber), expanded graphite, and mica. etc.
Also, the gasket itself may be constructed by laminating a plurality of materials. For example, a core material made of a strong material such as a stainless steel plate and laminated with sheets of different materials on both sides thereof, or a metal jacket gasket can be used.
The thickness of the gasket may be appropriately set in consideration of the aforementioned sealing properties and the height of the flow path to be formed, and an example is 0.1 mm to 10 mm.

(Flow path)
The flow path 4 has a function of allowing the introduced raw material fluid to flow and react to obtain a product. The shape and dimensions of the channel may be appropriately set in consideration of the ease of control of the reaction conditions (temperature, pressure, etc.), reaction efficiency, and the like. An example is a length of 10-1000 mm, a width of 1-1000 mm, and a thickness of 0.1-10 mm.

(fluid inlet/fluid outlet)
The fluid inlet 5 has the function of introducing fluid into the channel 4, and the fluid outlet 6 has the function of discharging the fluid in the channel to the outside. As shown in FIG. 1, the layered reactor according to this embodiment has a fluid inlet 5 provided on the lower plate and a fluid outlet 6 provided on the upper plate. That is, the stacked reactor 1 operates such that the fluid introduced from the bottom is discharged upward through the channel 4 .

Although one embodiment of the present invention has been described above, the embodiment can be modified in various ways.

For example, although the plates 2, 2 of the stacked reactor according to the present embodiment have been described as rectangular plates, hexagonal plates as shown in FIG. A rectangular plate, a circular plate as shown in FIG. 6(b), an elliptical or oval plate, or the like may be employed.

Further, the stacked reactor 1 according to the present embodiment has been described as having the fluid inlet 5 and the fluid outlet 6 provided on different plates 2, 2, respectively, but as shown in FIG. The plate 2 may be provided with both fluid inlets 5 and fluid outlets 6 . In this case, the stacked reactor operates such that the fluid introduced from the bottom is discharged downward through the channel 4 .

Moreover, although the stacked reactor 1 according to the present embodiment has been described as using two plates 2, 2 as described above, it may be configured using three or more plates. In this case, as shown in FIG. 8(a), it is also possible to configure the channels 4 to overlap vertically, and as shown in FIG. 8(b), the bottom layer and top layer of the laminated structure It is also possible to configure the two plates 21 , 21 arranged in the direction described above, and to use the rectifying plate 22 having a plurality of through holes 221 as the other plate.
When the rectifying plate 22 is used, when the fluid passes through the through-holes 221, the unevenness of the fluid flow in the flow path caused by bypassing, stagnation, etc. is eliminated, and a uniform reaction can occur.

As the rectifying plate 22 that functions in this way, for example, a plate member having through holes formed by machining or laser processing, a frame member covered with mesh or porous cloth, or a plate member provided with a Examples include those filled with porous bodies such as through-holes and open ceramics.
Further, a solid catalyst may be supported on the straightening plate 22 described above.

Further, in the stacked reactor 1 according to the present embodiment, temperature measuring means, pressure measuring means, thin tubes for supplying or discharging fluid, or the like are provided between the plates 2 and 2 and the gasket 3 as necessary. It may be sandwiched between them so that a part thereof is arranged in the channel 4 . In this case, it is preferable to use a material having a high compressibility, such as expanded graphite, which is capable of being compressed and deformed when assembling the stacked reactors, in order to sandwich them without gaps.

As described above, in the stacked reactor according to the present invention, by adjusting the shape of the surface of the plate 2 and/or the opening of the gasket 3, the thickness of the plate 2 and/or the gasket 3, and the number of stacked layers, the flow path It also has the advantage that the shape and dimensions of the can be changed relatively easily.

As in the present invention, a reactor with a catalyst laid on the inner wall of the reactor (hereinafter sometimes referred to as a "catalyst wall reactor") exhibits sufficient reaction performance (high conversion rate in methane reforming). It is important to design for
The void fraction, dimensionless numbers (Thiele number, Peclet number, Damkohler number) and heat transfer area, which are considered in the design of the catalytic wall reactor, will be described in order below.

(void fraction)
The void fraction (α) indicates the proportion of empty space inside the reaction vessel.
FIG. 9 is a diagram showing the dimensions of the catalyst layer in the catalyst wall reactor used to define the void fraction, (a) when laid in the recess of the plate, (b) without the recess. It shows the case laid on the plate surface.
In any case, from the true density ρ _real of the catalyst, the packing density ρ _b of the catalyst, and the dimensions A and B inside the plate reactor,
Void fraction α = 1 - {ρ _b × (B - A) / B} / ρ _real
can be defined as
The true density ρ _real can be obtained by a method such as measurement by a gas replacement method, and the packing density ρ _b can be obtained by a method such as measuring the volume of a predetermined weight of catalyst with a volumetric flask or the like.

(Chiele number)
As a condition of the catalyst particle size, it is preferable that the particle size is sufficiently small so that diffusion of the reaction molecules to the active point in the catalyst particle does not become a rate-limiting step, and the reaction rate is determined.
Assuming that the catalyst particles are spherical and a pseudo-first-order reaction is assumed as a condition for establishing a reaction rate-limiting region,
Thiele number φ=(dp/6)·(k/De) ^0.5
[Wherein, dp is the catalyst particle size (m), k is the rate constant or turnover frequency in the catalytic reaction (1/s), and De is the effective diffusion coefficient in the catalyst particle (m ² /s)]
and the Thiele number (φ) is preferably as small as possible, most preferably 0.1 or less.

(Péclet number, Damkohler number)
There are conditions under which the reaction performance of the catalyst is close to the reaction rate-determining region, and the design and operating conditions that define the reactor are restricted.
The first is that the reaction fluid does not have a concentration distribution in the direction perpendicular to the flow, that is, the speed at which the molecules reach the catalyst layer is sufficiently high relative to the flow velocity.
This is defined by the Peclet number Pe = (space velocity) / (diffusion velocity), and in a catalytic wall reactor,
Peclet number Pe=(u/L)/(D/d ² )
[Wherein, u is superficial velocity (m/s), L is catalyst layer length (m), D is diffusion coefficient (m ² /s), d is diffusion distance (m), superficial velocity u is obtained by dividing the flow rate by the cross-sectional area through which the fluid passes. ]
is represented as In a double-walled catalytic wall reactor as shown in FIGS. 9(a) and (b), the diffusion distance is d=B/2, and in a single-walled catalytic wall reactor, the diffusion distance is d=B. .
FIG. 10 is a diagram for explaining the definition of catalyst layer dimensions (L, W, H) in a catalyst wall reactor.

The second is that even if the molecules are consumed by the reaction in the catalyst layer, the reaction fluid does not have a concentration distribution in the direction perpendicular to the flow. That is.
This is defined by the Damkohler number Da = (reaction rate) / (diffusion rate), and in a catalyst wall reactor,
Damkohler number Da=k/(D/d ² )
[Wherein, k is the catalyst turnover frequency (1/s), D is the diffusion coefficient (m ² /s), and d is the diffusion distance (m)]
is represented as

As for the catalyst wall reactor, both the Peclet number Pe and the Damkohler number Da are 0.3 or less, preferably 0.1 or less, so that the reaction fluid is sufficiently supplied to the catalyst wall. Required for performance.

(Heat transfer area)
The heat transfer area (S) is the area of the catalyst layer facing the reactor wall.
In the catalyst wall reactor, the dimensions L, W, and H of the catalyst layer shown in FIG. , the heat transfer area is calculated as S=2 {LW+2(L+W)H}.
Moreover, as shown in (b) in the same figure, when it is laid on the plate surface without recesses, the heat transfer area is calculated as S=2LW.
_Note that FIG. 11 is a diagram for explaining the definition of the catalyst layer dimensions (L, d _i ) in a tubular catalyst-filled reactor. L is used to calculate the heat transfer area s=πd _i L.
The heat transfer area is preferably 1,000 to 2,000 mm ² , more preferably 2,000 to 20,000 mm ² per 1 mL of solid catalyst.

Hereinafter, the present invention will be specifically described based on examples and comparative examples, but the examples show preferred examples of the present invention, and the present invention is not limited by the examples. do not have.

[Example]
A stacked reactor shown in FIG. 1 was produced. A 300 mm×30 mm×7 mm SUS316 plate was used as the plate. The gasket used expanded graphite with outer dimensions of 300 mm x 30 mm x 0.5 mm and a slit of 250 mm x 4 mm in the center. In addition, a concave portion having a width of 80 mm and a depth of 4 mm is provided on the surface defining the flow channel (bottom surface of the flow channel) of the two plates, and the concave portion has a particle size of 0.3 mm (50 mesh) to 1 mm (16 mesh). ) was filled with 0.5 g of the NiO/Al ₂ O ₃ solid catalyst in total of 1.0 g, thereby laying the solid catalyst.
Furthermore, as shown in FIGS. 3 and 4, the recesses of the plate, with the solid catalyst laid thereon, were covered with a stainless steel mesh (200 mesh) having an opening of 75 μm, and were sandwiched and fixed between the gasket and the plate.

[Comparative example]
By the method described in Patent Document 1, 0.5 g of the solid catalyst sieved to 0.3 mm or less, and 1 mL of aluminum nitrate solution (concentration 0.04 mol / L) per 1 g of the solid catalyst were used to prepare the plate. , and the stainless steel mesh in the example was not used.

The stacked reactors of Examples and Comparative Examples thus prepared were installed in an electric furnace, and the reactor temperature was controlled to 525°C by a thermocouple outside the reactor, and then CH ₄ /CO ₂ was introduced from the fluid inlet. = about 60 sccm/about 60 sccm, and the dry reforming reaction of methane (CH ₄ +CO ₂ →2H ₂ +2CO) was allowed to proceed for 120 minutes.

FIG. 12 shows the results of pressure drop and methane conversion over time, which are reaction test results.
In the example, a reaction of carbon deposition of CH ₄ →C + 2H ₂ occurs as a side reaction of dry reforming, and as a result, the channel is blocked by the deposited carbon, and the pressure loss applied to the plate reactor increases by 68 kPa. there were.
On the other hand, in the comparative example, the pressure loss increased by 497 kPa.
From this, it was found that in the example, the pressure loss was suppressed as compared with the comparative example, and there was no sudden pressure rise.

A possible reason for this is the high void fraction [α=1-{ρ _b ×(BA)/B}/ρ _real ] in this embodiment.
That is, the void ratio α in this example is the true density (ρ _real ) of 4 g / L, the packing density (ρb) of 1.1375 g / L, the width between plates (A) of 0.54 mm, and the upper and lower catalyst laying Based on the width (B) of 3.54 mm between the bottoms of the parts, it is calculated to be 0.759.
The true density (ρ _real ) was measured by a gas replacement method, and the packing density (ρb) was calculated by measuring the volume of a given weight of the catalyst with a Mera flask or the like.
When the same calculation method was applied to the comparative example, the void ratio α was 0.753, which was lower than that of the example.
The high void fraction in this example is the result of fixing a solid catalyst with a large catalyst particle size.

In the examples, the methane conversion rate by gas analysis was 20 to 27%, which was comparable to that of the comparative example and a general tubular catalyst packed bed reactor.
One of the reasons for this is that the present example was able to be tested in the reaction rate-determining region.
In the catalyst assumed to be spherical as a condition for establishing a reaction rate-determining region, Example [L = 80 mm, W = 4 mm, H = 1.37 mm, d (diffusion distance) = 4.61 mm] and Comparative Example [L = 80 mm , W = 4 mm, H = 1.34 mm, d (diffusion distance) = 1.62 mm].
In this test, it was estimated that k=1/s, De=1×10 ⁻⁷ m ² /s, D=1×10 ⁻⁴ m ² /s, u=0.4 m/s.

As shown in Table 1, the Thiele number φ was less than 0.1 in both the examples and the comparative examples. Moreover, since both the Peclet number Pe and the Damkohler number Da were 0.3 or less, it is considered that the reaction fluid was sufficiently supplied to the catalyst wall.
In addition, although the Peclet number Pe slightly exceeded 0.1 in both the examples and the comparative examples, the Thiele number φ and the Damkohler number Da were below 0.1. I found out that

Another reason is that the heat transfer area was larger than that of the conventional tubular catalyst packed bed reactor.
Since the methane dry reforming studied in this example and comparative example is a large endothermic reaction with a reaction enthalpy of ΔHr=247 kJ/mol, it is also important to secure heat supply to maintain the reaction temperature.
The heat transfer area (S = 2 {LW + 2 (L + W) H}) was 871 mm ² in the example (L = 80 mm, W = 4 mm, H = 1.37 mm), and in the comparative example (L = 80 mm, W = 4 mm, H = 1.34 mm), it was 866 mm ² , which was slightly larger in the example and exceeded the heat transfer area of 790-808 mm ² in the conventional tubular catalyst packed bed reactor. .
This indicates that the catalyst wall type method, in which the catalyst layer is fixed to the wall surface with a wide and thin thickness, has a structurally large heat transfer area.

According to the present invention, in the production of hydrogen or synthesis gas by reforming methane, it is possible to take a longer period of time than before to perform flow path clogging due to carbon deposition or catalyst maintenance. As a result, maintenance frequency can be reduced, and as a result, operation can be performed with reduced running costs. In addition, the present invention is not limited to methane reforming reactions accompanied by carbon deposition, which is a factor of channel clogging, but is also useful in a wide range of reaction systems involving reforming of carbon compounds and deposition of solids.

1: Laminated Reactor 2, 21: Plate 22: Straightening Plate 221: Through Hole 3: Gasket 4: Channel 5: Fluid Inlet 6: Fluid Outlet 7, 71, 72: Solid Catalyst 8: Support

Claims (4)

A layered reactor for reactions involving solid deposition,
a channel formed by stacking a plurality of plates at predetermined intervals via gaskets;
a fluid inlet and a fluid outlet provided in one of the plates and communicating with the channel;
a powdery or granular solid catalyst with a particle size of greater than 0.3 mm;
a laying portion for the solid catalyst provided on a wall surface facing the flow path;
a support covering the laying portion of the solid catalyst and having openings smaller than the particle size of the solid catalyst;
with
the support is sandwiched between one of the plates and a gasket;
A stacked reactor in which the solid catalyst is fixed to the wall surface by the support. 2. The stacked reactor according to claim 1, wherein the solid catalyst-laying portion is provided in a concave portion provided in a wall surface of the plate or gasket facing the channel. 2. The stacked reactor according to claim 1, wherein the solid catalyst-laying portion is provided on a wall surface of the plate or gasket that faces the channel and has no recess. the plate
two plates arranged on the bottom and top layers of the laminated structure;
a straightening plate having a plurality of through-holes disposed between the two plates,
4. The stacked reactor according to any one of claims 1 to 3 , wherein the fluid inlet and the fluid outlet are arranged opposite to each other with respect to the straightening plate.